Apparatus and method for deterring birds by laser

ABSTRACT

The invention concerns an apparatus and a method for deterring birds, comprising a frame fixedly disposed on a structure; a laser light generator connected with the frame, including a laser light source for generating a laser light beam; a supply circuit for supplying the laser light source; driving means connected with the laser light generator, for having at least a part of the laser light generator move; and a control element for controlling the laser light source and the drivable part of the laser light generator, wherein the driving means are arranged for causing a movement to be executed of at least a drivable part of the laser light generator. Thus, an apparatus and a method are obtained having a greater effect in deterring birds.

This application is a National Stage of International Application No.PCT/NL2014/050306 filed May 15, 2014, which claims priority toNetherlands Application No. 2010805 filed May 15, 2013.

The present invention concerns the deterring of birds. Birds can causenuisance problems, in particular at airports for airplanes andhelicopters, but also in orchards, where the birds typically consume thefruit.

According to the prior art, an apparatus for deterring birds is knownwhich is provided with a fixedly disposed frame, a laser light generatorconnected with the frame, including a laser light source for generatinga laser light beam, a supply circuit for supplying the laser lightsource, driving means connected with the laser light generator, forhaving at least a part of the laser light generator move, and a controlelement for controlling the laser light source and the drivable part ofthe laser light generator.

This known apparatus upon activation generates a laser beam, which is todeter the birds. As the apparatus is fixedly disposed, the laser beamwill be stationary and the deterrent effect is low, in particular as thebirds habituate to the presence of the laser beam.

The object of the invention is to provide such an apparatus, whosedeterrent effect is greater.

This object is achieved in that the driving means are arranged forcausing a repetitive movement to be executed of at least a drivable partof the laser light generator. These measures thus cause a moving laserbeam, which has a much greater dissuasive and deterrent effect than astationary beam. It is noted that the birds see the laser beam as aphysical object and are thereby deterred faster.

The invention also concerns a method for deterring birds, whichcomprises generating in a fixedly disposed apparatus a bird deterrentlaser beam, wherein the laser light beam performs a repetitive movement.

According to a first embodiment, the drivable part of the laser lightgenerator is arranged for causing the laser light beam to move in asingle direction. This embodiment has the advantage of a simpleconstruction.

According to another embodiment, the drivable part of the laser lightgenerator is arranged for causing the laser light beam to move in asecond direction. With this, more variation in the pattern is obtained,so that habituation of the birds will occur less rapidly.

It is possible, in principle, to have the laser light source move, inparticular when the laser light source has a simple construction. Whenquick, high-frequency movements are to be performed, however, it ispreferred that the laser light generator comprises a deflecting deviceconnected after the laser light source, provided with mirrors; that thelaser light source is fixedly connected with the frame, and that thedriving means are arranged for driving the deflecting device. Thisconfiguration can be used not only with the laser beam movable in asingle direction, requiring only a single movable mirror, but also witha laser beam movable in two directions, requiring two movable mirrors orother deflecting elements.

As the apparatus according to the invention attempts to deter birds, itis important that the birds actually see the deterrent laser beam or thelight spot generated thereby. In particular with air traffic, the laserbeam hindering pilots or other persons should be prevented. To this end,it is preferred that the laser light source is arranged for generatinglaser light having a wavelength of between 300 nm and 400 nm. Theinvention also concerns a method, whereby laser light having awavelength of between 300 nm and 400 nm is generated. It is notedincidentally that it is also possible to work with light visible topeople, in particular green light.

While a single laser beam may scare away the birds, the area where thebirds are in fact scared away by the laser beam is small. Accordingly,there is a need for a phenomenon that occupies a larger volume, so thatthe deterrent effect extends over a larger area. This object is achievedin that the control element is arranged for causing the laser beam tomove with such a high frequency that a bird perceives the moving laserbeam as a surface. The surface then apparently occupies a considerablylarger volume than the stationary laser beam, so that the deterrenteffect is greater. This embodiment also concerns a method, whereby thelaser beam is moved with such a high frequency that a bird perceives themoving laser beam as a surface.

Aiming the laser beam at the ground causes a light spot, which, inparticular when it moves towards the birds, deters the birds. The laserbeam per se, when it has sufficient power, and the environment issufficiently dark, is also visible to birds. To be able to utilize botheffects, it is attractive when the apparatus is arranged for aiming thelaser beam both at fixed structures and into the air.

When the apparatus is placed on a moving structure, such as a ship, thedanger exists of the laser beam radiating to above the horizon, which isundesirable. To prevent this, for such a situation, the apparatus isprovided with means for limiting the angle of elevation of the exitinglaser beam. Also, it is possible, in combination with the above featureor without this feature, to dynamically adjust the angle of elevationand the direction to the movements of the structure.

To enhance the repellent effect of the laser beam, it is preferred thatthe apparatus is arranged for causing the laser beam to move jerkily.

To protect structures such as wind turbines or drilling rigs from birds,the apparatus, according to a preferred embodiment, is arranged forcausing a figure to be described which forms the envelope of astructure.

After the birds have been deterred by the apparatus according to theinvention, they typically return to the position they have been deterredfrom, in particular when these positions are attractive to the birds,for instance because of the presence of edible crops. To deter the birdsagain upon their return, a preferred embodiment proposes that thecontrol element is arranged for causing a program to be executedrepeatedly by the laser beam. It is then possible that the program isexecuted at regular intervals, but also that the frequency is irregular.Also, it is possible that the program is repeated only at twilight andin darkness.

Because of the simple design, it is attractive when the control elementis arranged for each time executing the same program.

It is also possible, however, that the control element is arranged foreach time executing a different program. The deterrent effect is thengreater as the birds are surprised by the pattern changing each time,since habituation by the birds will hardly occur. In that case, thecontrol element has to be arranged for controlling the differentpatterns.

In particular when the apparatus works autonomously, that is, withoutdetection or prediction of birds, it is attractive when the controlelement is arranged for executing a program at predetermined points oftime. These points of time may be determined with varying intervals, as,for instance, determined by a random generator, but it is also possiblethat the program is executed at fixed points of time or with fixedintervals. It is incidentally noted that it is also possible to take theinfluence of the light into account in determining the points of time atwhich the program is executed and in the choice of the program.

According to a preferred embodiment, the control element is providedwith input means and the input means are arranged for inputting theproperties of the path to be described by the laser. The term propertiesis understood to mean, for instance, extreme positions or parts of thepath.

To avoid unnecessary energy consumption and to prevent bird habituationto a pattern, the apparatus, according to a preferred embodiment, isprovided with a bird detection element for detecting birds in thesurroundings of the apparatus, the bird detection element is connectedwith the control element, and the control element is arranged forexecuting a program after detection of a number of birds by the birddetection element. With these features, the program is executed onlywhen birds are actually present. The invention further concerns amethod, whereby after detection of a number of birds the laser beamexecutes a program.

Alternatively, or in combination with the above-mentioned feature, theapparatus is provided with a prediction element for predicting anairplane approaching the surroundings of the apparatus, the predictionelement is connected with the control element and the control element isarranged for executing a program when the prediction element predictsthe approach of an airplane. An airplane is understood to mean any bodytraveling through the air, such as a helicopter or an unmanned airplane.This feature takes the high speed of airplanes into account, so that thebirds will have been scared away in good time before the arrival of theairplane in the area where the apparatus is disposed. This embodimentalso concerns a method, whereby after detection of a number of birds thelaser beam executes a program.

According to a further preferred embodiment, the apparatus is arrangedfor generating a laser beam moving fast in a direction, which isperceived by birds as a surface, upon prediction of the approach of anairplane. By generating such a ‘surface’, the deterrent action againstthe birds is enhanced, while through a suitable positioning of the‘surface’ with respect to the runway, birds are prevented fromapproaching the runway.

In some situations, for instance in glaring sunlight, the laser beamsand the spots on the ground or on fixed structures are poorlyperceptible to the birds. To be able to scare the birds effectively insuch a condition too, a further embodiment proposes that the apparatusis provided with alternative bird deterrent means for deterring birds ina different manner than with laser light and that the control element isarranged for controlling the alternative bird deterrent means. Thepresence of glaring sunlight or light coming from a different source canbe detected by a light detector.

Although the possibility of activating the alternative bird deterrentmeans prior to or after the laser light generator is not excluded, it ispreferred that the control element is arranged for activating thealternative bird deterrent means simultaneously with the laser lightgenerator.

Furthermore, it is preferred when the control element is arranged for,after executing a program with the laser light generator, executing apresence detection of birds and, in the presence of birds, activatingthe alternative bird deterrent means. This makes it possible toinitially utilize the bird deterrent means working with laser light and,in situations where these have proved not to be effective, to utilizealternative bird deterrent means.

The alternative bird deterrent means comprise, for instance, anapparatus for generating a water jet or means for producing sound.

WO2009/010961 discloses a positional deterrence device that is aimed atthe azimuth and elevation of a detected intruding animal. To create amultidirectional coverage, a rapid scanning may be realized to provide ascanning volume. However, this disclosure does not persistently keepbirds away from a volume defined by a fixed structure such as a runway.

The present invention will now be elucidated on the basis of theaccompanying drawings in which the figures represent the following:

FIG. 1: a schematic side view of an apparatus according to theinvention;

FIG. 2: a schematic top plan view of the apparatus depicted in FIG. 1;

FIG. 3: a side elevation of an apparatus according to the invention andthe laser beam generated thereby;

FIG. 4: a top plan view of a specific configuration according to theinvention;

FIG. 5: a top plan view of a variant of the configuration represented inFIG. 4;

FIG. 6: a perspective view of another embodiment; and

FIG. 7: a side view of a configuration suitable specifically for windturbines.

The apparatus depicted in FIGS. 1 and 2, designated as a whole with 1,comprises a fixedly disposed frame 2, in which a laser source 3 ismounted, with its optical axis 4 directed upwards. Placed above thelaser source 3 and connected with the frame 2 are a pair of bearings 5,in which a shaft 6 is rotatably bearing-mounted. The shaft 6 is drivablefor rotation by an electric motor 7. Arranged on the shaft is a mirror8. By drive of the electric motor 7 the rotation position of the mirror8 is adjusted to thereby control the amount of deflection of the laserbeam 4 exiting from the laser source 3 in a horizontal plane. For thesupply of the laser source 3 a supply unit 9 is present, and for thecontrol of the electric motor 7 and the laser source 3 a control unit 10is in place. The whole is accommodated in a housing 11. The supply unitmay be formed by a battery, typically combined with a PV panel, but mayalso be formed by a connection to a supply network.

Upon activation of the apparatus, by means of the supply unit 9 and thecontrol unit 10 the laser source 3 is switched on so that a laser beam 4exits from the laser source 3 along the optical axis. This laser beam 4strikes the mirror 8, which has an oblique position, so that the laserbeam 12 reflected by the mirror 8 exits in a horizontal direction. Withthis, the apparatus is suitable for generating a stationary laser beam,which, as has been described above, exits in horizontal direction andwhich is perceived by the birds, so that the birds are scared away. Thelaser beam 12, under the influence of the control unit 10 and the mirror8, may also exit upwardly inclined or downwardly inclined. In the lattercase the laser beam will then hit the ground and cause a light spot onthe ground which scares away the birds.

The above concerns a stationary solution; it is also possible, as hasalready been explained, to utilize a movable laser beam. To this end, inthe above embodiment, the electric motor 7 is to drive the mirror suchthat the exiting laser beam 12 moves in the vertical direction. By thedynamics resulting from this, the birds are deterred more easily. Such asituation is represented in FIG. 3. When the mirror is driven with ahigh speed, the birds perceive the laser beam as a surface 13. Thisembodiment requires a fast moving mirror. While to this end use can bemade of a fast rotating electric motor, as in the above-describedembodiment, it is also possible to utilize for this purpose an electricdriving element having the structure of a galvanometer.

FIG. 4 shows a situation in which two apparatuses 1 a, 1 b like the oneshown in FIG. 3 are placed on opposite sides of a runway 15. With these,two laser beams 12 are generated which, as a result of their rapidmovement, apparently form a vertical surface. In the situation shown inFIG. 4, it is clear how these surfaces keep the runway 15 clear of birds16 in order to minimize the danger of an airplane 17 hitting a bird. Itis obviously necessary here that prior to generating the radiationpattern represented in FIG. 4 the birds 16 be scared off the runway 15,for instance by having either or both of the laser beams 12 sweep abovethe runway 15.

Naturally, other configurations are possible; thus, it is possible todispose the apparatuses 1 in such a manner that the apparent surfaces 13extend transversely to the runway 15. This prevents birds 16 from movingin the longitudinal direction of the runway to the part where theairplanes 17 land and take off. It is incidentally noted that it is moreattractive when only a single apparatus 1 according to the invention ispresent and the laser beam exiting from the apparatus 1 moves not onlyin the vertical plane but also in the horizontal plane. Particularlywhen the movements in the vertical plane are fast and the movements inthe horizontal plane slower, a surface is obtained that, to the birds,apparently swerves. This configuration, for that matter, can also beused in other situations.

Furthermore, the above described apparatuses may be coupled with aprediction device for predicting the arrival of an airplane, so that theapparatus is switched on only then. To this end, a link with theinstallations of the air traffic control can be made. Also, a link witha presence detector for birds can be made in order to generate a laserbeam only when birds are present.

Finally, FIG. 6 shows a situation in which an apparatus 21 according tothe invention is disposed on a helicopter platform 22, for instance onan oil rig. On a steel construction 23, which is part of an oil rig notfurther shown, the helicopter platform 22 has been placed, as well as anapparatus 21 according to the invention. This apparatus is arranged forgenerating a laser beam 25, which is directed towards the helicopterplatform 22. The laser beam can then move over the platform 22 in bothdirections to scare away birds present on the platform. Furthermore, theapparatus according to the invention comprises a water cannon 27 placedon the apparatus 21. The control of the water cannon 27 is thenprogrammed such that the water jet 28 exiting from the water cannon 27is aimed at the same part of the platform 22 as the laser beam 25exiting from the apparatus 21. Upon simultaneous operation of the laserbeam 25 and the water jet 28, the birds are deterred in two ways at thesame time. It is also possible, however, to use the water jet as analternative to the laser beam, for instance when due to glaring sunlightthe laser beam is poorly visible to the birds. Also, it is possible touse the two media alternately.

Also in this embodiment, the laser source or the water cannon may bearranged to be activated only upon detection of birds or in anticipationof the arrival or departure of a helicopter. Finally, as in theinitially discussed embodiment, it is possible to aim the water jet orthe laser beam at the place where birds have been observed.

The embodiment shown in FIG. 7 is suitable for placement on a windturbine 30. The apparatus 31 according to the invention is placed on aring 32, which is arranged rotatably around the tower 33 of the windturbine 30. The apparatus 31 is movable along the ring 32 by drive meansnot shown. The apparatus 31 is arranged for radiating a laser beam 34which extends obliquely upwards at an angle to the tower 33. The angleis then chosen such that the laser beam 34 upon rotation of theapparatus along the ring describes a cone, the cone enveloping the pathof the blades 35 of the wind turbine 30.

The invention claimed is:
 1. An apparatus for deterring birds from afixed structure, comprising: a frame fixedly disposed on a structure; alaser light generator connected with the frame, including a laser lightsource for generating a laser light beam; a supply circuit for supplyingthe laser light source; driving means connected with the laser lightgenerator, for having at least a part of the laser light generator move;and a control element for controlling the laser light source and thedrivable part of the laser light generator, wherein the driving meansare arranged for causing a movement to be executed of at least adrivable part of the laser light generator wherein the control elementis arranged at aiming a laser beam both at the fixed structure and intothe air so as to clear the fixed structure by sweeping the laser beamover the fixed structure, characterized in that the control element isfurther arranged in that subsequently, the laser beam is caused to moveby the control element with such a high frequency along side the fixedstructure that the moving laser beam is perceived as a surface thatkeeps the birds away from a volume defined by the surface and the areaof the fixed structure.
 2. The apparatus according to claim 1, whereinthe laser light generator comprises a deflection device connected afterthe laser light source and provided with mirrors, that the laser lightsource is fixedly connected with the frame and that the driving meansare arranged for driving the deflection device.
 3. The apparatusaccording to claim 1, wherein the laser light source is arranged forgenerating laser light having a wavelength of between 300 nm and 400 nm.4. The apparatus according to claim 1, wherein the control element isarranged for causing the laser beam to move in a vertical plane withfast movements in a horizontal plane with slower movements, so that anapparent surface is obtained that swerves.
 5. The apparatus according toclaim 1, wherein the apparatus is arranged to be placed on a movingstructure, such as a ship, and that the apparatus is provided with meansfor limiting the angle of elevation of the exiting laser beam.
 6. Theapparatus according to claim 1, wherein the apparatus is arranged forcausing the laser beam to move jerkily.
 7. The apparatus according toclaim 1, wherein the apparatus is arranged for causing a figure to bedescribed which forms the envelope of a structure.
 8. The apparatusaccording to claim 1, wherein the control element is arranged forrepetitively causing a program to be executed by the laser beam.
 9. Theapparatus according to claim 8, wherein the control element is arrangedfor each time executing the same program.
 10. The apparatus according toclaim 8, wherein the control element is arranged for each time executinga different program.
 11. The apparatus according to claim 8, wherein thecontrol element is arranged for executing a program at predeterminedpoints of time.
 12. The apparatus according to claim 8, wherein thecontrol element is provided with input means and that the input meansare arranged for inputting properties of the path to be described by thelaser beam.
 13. The apparatus according to claim 8, wherein theapparatus is provided with a bird detection element for detecting birdsin the surroundings of the apparatus, that the bird detection element isconnected with the control element and that the control element isarranged for executing a program after detection of a number of birds bythe bird detection element.
 14. The apparatus according to claim 8,wherein the apparatus is provided with a prediction element forpredicting an airplane approaching the surroundings of the apparatus,that the prediction element is connected with the control element andthat the control element is arranged for executing a program when theprediction element predicts the approach of an airplane.
 15. A methodfor deterring birds from a fixed structure, which comprises generatingin a fixedly disposed apparatus a bird deterring laser beam, wherein thelaser light beam performs a repetitive movement wherein a laser beam isaimed both at the fixed structure and into the air so as to clear thefixed structure by sweeping the laser beam over the fixed structure, andwherein subsequently, the laser beam is caused to move with such a highfrequency along side the fixed structure that the moving laser beam isperceived as a surface that keeps the birds away from a volume definedby the surface and the area of the fixed structure.